Dirt Bike Engine
Dirt Bike Engine Parts at JJ Motorsports
Discover a full range of dirt bike engine components for rebuilding or upgrading your performance from JJ Motorsports. From crankshafts to cylinder heads and piston kits, these precision-engineered components ensure reliable performance. For additional upgrades, check out our full selection of off-road dirt bike parts to keep your engine running at peak efficiency on the track or trails.
Shop trusted brands like Wiseco for forged piston kits and K&N for high-flow oil filters. Explore related categories such as Dirt Bike Air and Fuel for intake upgrades or Dirt Bike Exhaust for complete systems.
Browse our in-stock inventory below with same-day shipping and expert support. Questions? Contact us for fitment advice!
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- Qty in Cart
- Quantity
- Price
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On Sale
COMETIC Top End Gasket Kit - 79 mm - Honda C3635
COMETIC
MSRP: $67.95Now: $61.16Was: $67.95A quality top end gasket kit is critical for maintaining cylinder pressure and preventing catastrophic coolant or oil leaks—especially when running high-horsepower naturally aspirated or...09347846- SKU:
- 09347846
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $67.95Now: $61.16Was: $67.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Kawasaki C3696
COMETIC
MSRP: $85.95Now: $77.36Was: $85.95A failed head gasket means downtime and expensive engine damage—especially on high-output 4-stroke engines running elevated cylinder pressures. The COMETIC Top End Gasket Kit delivers the sealing...09347848- SKU:
- 09347848
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $85.95Now: $77.36Was: $85.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Honda C3733
COMETIC
MSRP: $85.95Now: $77.36Was: $85.95A failing top end gasket compromises combustion sealing and allows coolant or oil to escape—both catastrophic for engine reliability and performance. This COMETIC kit delivers OEM-correct fitment...09347850- SKU:
- 09347850
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $85.95Now: $77.36Was: $85.95 -
On Sale
COMETIC Top End Gasket Kit - KTM/Husqvarna/Gas Gas C3636
COMETIC
MSRP: $47.95Now: $43.16Was: $47.95A failed top-end gasket can cost you race time, engine damage, and thousands in repairs. The COMETIC C3636 kit delivers OEM-quality sealing with performance-grade materials engineered to handle the...09347801- SKU:
- 09347801
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $47.95Now: $43.16Was: $47.95 -
On Sale
COMETIC Top End Gasket Kit - 80 mm - Yamaha C3766
COMETIC
MSRP: $79.95Now: $71.96Was: $79.95A failing top-end gasket compromises combustion chamber sealing, killing power output and risking catastrophic engine damage. The COMETIC C3766 kit delivers the precision sealing your high-output...09347852- SKU:
- 09347852
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $79.95Now: $71.96Was: $79.95 -
On Sale
COMETIC Top End Gasket Kit - KTM/Husqvarna/Gas Gas C3811
COMETIC
MSRP: $79.95Now: $71.96Was: $79.95A failed top end gasket can sideline your bike and compromise engine integrity—especially when you're pushing high horsepower through naturally aspirated or forced induction setups. This Cometic kit...09347803- SKU:
- 09347803
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $79.95Now: $71.96Was: $79.95 -
On Sale
COMETIC Top End Gasket Kit - 91 mm - KTM C3784-EST
COMETIC
MSRP: $74.95Now: $67.46Was: $74.95A quality gasket kit is non-negotiable for any top-end rebuild—it's your seal against compression loss, coolant weeping, and catastrophic engine failure. The COMETIC C3784-EST delivers the sealing...09347854- SKU:
- 09347854
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $74.95Now: $67.46Was: $74.95 -
On Sale
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3786
COMETIC
MSRP: $78.95Now: $71.06Was: $78.95A failing top end gasket will compromise combustion sealing and cost you power—or worse, create catastrophic engine damage. This Cometic kit delivers the complete solution with precision-engineered...09347855- SKU:
- 09347855
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $78.95Now: $71.06Was: $78.95 -
On Sale
COMETIC Top End Gasket Kit - 79 mm - Kawasaki C3787
COMETIC
MSRP: $84.95Now: $76.46Was: $84.95A failing head gasket will cost you power, reliability, and time on the track or in the shop. COMETIC's multi-layered steel design with Viton rubber coating distributes combustion pressure evenly...09347856- SKU:
- 09347856
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $84.95Now: $76.46Was: $84.95 -
On Sale
COMETIC Top End Gasket Kit - 95 mm - KTM/Husqvarna/Gas Gas C3604-EST
COMETIC
MSRP: $74.95Now: $67.46Was: $74.95A failing top end gasket compromises combustion sealing, kills power, and invites catastrophic engine damage. The COMETIC C3604-EST delivers OEM-spec sealing reliability with advanced multi-layer...09347807- SKU:
- 09347807
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
MSRP: $74.95Now: $67.46Was: $74.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Honda C3801
COMETIC
MSRP: $85.95Now: $77.36Was: $85.95A failed head gasket means catastrophic engine damage and costly downtime. The COMETIC Top End Gasket Kit delivers the sealing integrity and thermal management your high-output engine demands,...09347859- SKU:
- 09347859
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $85.95Now: $77.36Was: $85.95 -
On Sale
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3813
COMETIC
MSRP: $87.95Now: $79.16Was: $87.95A compromised top end gasket is one of the quickest ways to lose compression, power, and reliability. The COMETIC C3813 Top End Gasket Kit is engineered for high-output 4-stroke engines that demand...09347863- SKU:
- 09347863
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $87.95Now: $79.16Was: $87.95 -
On Sale
COMETIC Top End Gasket Kit - KTM C3818
COMETIC
MSRP: $47.95Now: $43.16Was: $47.95A quality top-end gasket kit is essential for maintaining cylinder pressure, preventing coolant leaks, and maximizing power output on high-performance 4-stroke engines. Cometic's EST (Extreme Sealing...09347864- SKU:
- 09347864
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $47.95Now: $43.16Was: $47.95 -
On Sale
COMETIC Top End Gasket Kit - 47 mm - Kawasaki/Suzuki C7682
COMETIC
MSRP: $28.95Now: $26.06Was: $28.95A failing top-end gasket can compromise combustion chamber sealing, reduce ring seal efficiency, and lead to catastrophic engine failure. The COMETIC C7682 kit delivers OEM-spec sealing with...09347866- SKU:
- 09347866
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $28.95Now: $26.06Was: $28.95 -
On Sale
COMETIC Top End Gasket Kit - 98 mm - Yamaha C3178-EST
COMETIC
MSRP: $90.95Now: $81.86Was: $90.95A failed head gasket means catastrophic engine damage and downtime you can't afford. The COMETIC Top End Gasket Kit with EST (Extreme Sealing Technology) delivers the reliability and thermal...09347825- SKU:
- 09347825
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $90.95Now: $81.86Was: $90.95 -
On Sale
COMETIC Top End Gasket Kit - 99 mm - Yamaha C3279-EST
COMETIC
MSRP: $90.95Now: $81.86Was: $90.95A failing top-end gasket will cost you power and reliability—and on high-output 4-stroke engines running boost or chasing peak naturally aspirated performance, factory gaskets often can't handle the...09347829- SKU:
- 09347829
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $90.95Now: $81.86Was: $90.95 -
ACERBIS X-Power Kit - Black - Honda 2985460001
ACERBIS
$76.95Off-road riding exposes your engine casings to constant abuse from rocks, mud, and debris that can compromise critical engine components and lead to expensive damage. The ACERBIS X-Power Kit provides...09402209- SKU:
- 09402209
- Availability:
- Ships Same Business Day
- Weight:
- 1.45 LBS
$76.95 -
ACERBIS X-Power Kit - Red - Honda 2985460227
ACERBIS
$76.95Off-road riding exposes your engine casings to constant punishment—mud, rocks, and debris can compromise protective covers and create costly damage. The ACERBIS X-Power Kit shields critical engine...09402210- SKU:
- 09402210
- Availability:
- Ships Same Business Day
- Weight:
- 1.45 LBS
$76.95 -
Hot Cams Intake Camshaft Stage 2 Suzuki RM-Z250 2007-2009 2087-2IN
HOT CAMS
$309.70If you're running a stock RM-Z250 and want measurable performance gains without major engine modifications, the Hot Cams Stage 2 Intake Camshaft is the bolt-on solution. This CNC-machined upgrade...09251587- SKU:
- 09251587
- Availability:
- Ships Same Business Day
- Weight:
- 0.84 LBS
$309.70 -
Hot Cams Camshaft Stage 1 Honda CRF450R 2017-2020 HC00053
HOT CAMS
$396.85If you're running a stock Honda CRF450R, you're leaving power on the table. The Hot Cams Stage 1 Camshaft unlocks 5–10% additional horsepower and torque while sharpening throttle response across the...09251593- SKU:
- 09251593
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
$396.85
